Saturdays with Daniel.

Where Aviation meets Desktop.

JS Potchefstroom

In 2012 Jonker Sailplanes penetrated the Open Class market with the introduction of the 21m version of the JS1. The outboard wing and wing-wingtip junction was redesigned to accommodate the higher wing loads and a higher maximum take-off mass of 720kg [1587 lb] (increased from 600kg). The 21m wingtips have integral water ballast tanks with a capacity of 17 litres [4.5 gallons US ] each with cockpit control allowing the pilot to jettison the wingtip water ballast separately to the main wing and tail fin tanks. The JS1C-21 not only displays an excellent glide ratio at moderate speeds, but also at high speeds and maintains its outstanding climbing performance. It has proven its popularity during the 2017 WGC in Benalla with 23 out of 35 competitors flying the JS1C in the Open Class. Seven of the first 10 places were claimed by JS1 pilots with Russell Cheetham and Andy Davis taking the gold and bronze medals respectively.


 Jonker Sailplanes Pty Ltd. (JS) is a privately owned, South African company that designs, manufactures, and maintains sailplanes from their main facility based at the Potchefstroom Airfield. It was originally a small team of three engineers and three technicians who combined their knowledge to produce a sailplane that would win competitions and fly beautifully. These six were the beginning of the original JS1 success story. Ten years later there are 16 qualified engineers and more than 110 employees working in the Jonker Sailplanes factory in South Africa. With M&D Flugzeugbau in Germany now further strengthening the team, the company has become a force to be reckoned with!